1. Field of the Invention
The present invention relates to large diameter gate valves and remote control thereof in an opening and closing action.
It has been proposed to harness ocean thermal energy by utilizing an economic nonpolluting power source comprising a heat engine which uses warm ocean surface water as the heat source and the cold subsurface water as a heat sink for converting thermal energy to electrical energy. From an economical point of view it is necessary that a bank of such heat engines be operated to justify the cost of installation and operation thus requiring a relatively large volume of cold sea water to be pumped to the surface for cooling or condensing a gas after driving a turbine for recirculation and vaporization of the gas by warm ocean surface water for again driving the turbine in an endless cycle. A proposed diameter of the casing, for obtaining the cold sea water, is approximately 40 feet (12.20 meters). Since the large diameter casing must extend downwardly into the ocean a depth of 1500 feet (457.20 meters) or more some means must be provided in the depending end portion of the casing for opening and closing its passageway.
2. Description of the Prior Art
The prior art, such as U.S. Pat. No. 2,759,699 and British Pat. No. 653,266 (5--1951), has generally comprised sleeve valves capable of opening and closing a fluid passageway or conductor by fluid pressure applied to a hydraulic type cylinder forming a part of or secured to the valve.
This invention is distinctive over this type of valve control by providing a floatation ring equipped sleeve valve which is balanced with respect to fluid pressure or a hydrostatic head thereagainst which is opened and closed by inflating and deflating floatation chambers forming a part of the sleeve valve.
This invention is distinctive over my copending application by eliminating the jacket surrounding the casing ports and the continuation of the casing string beyond the valve and further by confining the sleeve valve within the ported end portion of the casing.